The Schalke squad were confronted by angry fans after their inevitable relegation from the Bundesliga was confirmed on Tuesday.
|Photo: Michael Welsing, CC BY-SA 2.0|
The club have started an investigation into an encounter between the team and some groups of fans early on Wednesday morning.
"During the course of the encounter, some currently unidentified individuals overstepped boundaries that are non-negotiable for FC Schalke 04," said the statement.
"Despite the understandable frustration and anger with our relegation to the Bundesliga 2, the club can never accept the physical endangerment of our players and staff.
"That is exactly what occurred during last night's confrontation. The club strongly condemns this behaviour and stands behind our staff.
"An investigation into the incident is already underway. FC Schalke 04 will give no further comment on this matter until things are cleared up."